The peculiarities of modulating action of ricin and agglutinin ricin, and their complexes with sugars on the respiratory burst in neutrophils inducedby the chemotactic peptide

It was shown that agents inducing phagocytosis (zymosan, lectins) cause cha nges in the number of receptors responsible for fast neutrophil reaction (c hemotaxis or respiratory burst) or inhibit the binding of the agonist to it s receptor. Among lectins are ribosome-inactivating proteins of type II ric in and agglutinin ricin, which penetrate the cell by binding to mannose and galactose receptors. It was shown that ribosome-inactivating proteins of t ype II can exhibit the properties of the antagonist of the receptor N-formy lmethionylleucylphenyl alanine. Ricin is more effective in modulating the r espiratory burst induced by the chemotactic peptide than agglutinin ricin. The modulating effect of ribosome-inactivating proteins of type II on neutr ophils is likely to be mediated by their interaction with galactose rather than mannose receptors. Presumably, the affinity of ribosome-inactivating p roteins to galactose receptors increases with increasing amount of sacchari des bound to the protein molecule. The modulating effect of ribosome-inacti vating proteins of type II on the respiratory burst of neutrophils induced the chemotactic peptide is due to the structural peculiarities of these pro teins.